Conventionally, in an vehicle-mounted device such as a navigation apparatus, narrow-band wireless communication is performed with a roadside apparatus placed on a road by using DSRC (Dedicated Short Range Communication) and the like, and information provision can be received from a center apparatus via the roadside apparatus. More specifically, only while a vehicle is within a communication range of the roadside apparatus, two-way communication of the vehicle-mounted device of a vehicle and the roadside apparatus is enabled, and during this period, the center apparatus distributes various kinds of content information such as advertisement information via the roadside apparatus.
The content information is divided into a direct type and an accumulation type according to the timing of reproduction. The direct type refers to content information of a type which is directly reproduced as soon as the content information is received, whereas the accumulation type refers to content information of a type which is temporarily accumulated instead of being reproduced immediately when it is received, and is reproduced when the vehicle reaches a certain point (location) or the like. In general, a direct type is more often than not the information with higher necessity, and the priority of reproduction is set to be higher than an accumulation type.
Meanwhile, as one kind of content information the voice reading of which is performed, the one of a highway radio is cited. A highway radio is traffic information or the like which is provided at each of certain locations. (For example, see Patent Document 1).
Conventionally, various arts have been developed with regard to reproduction of music information. For example, there is a method (for example, see Patent Document 1), in which when reproduction of music information is suspended, and reproduction of ITS (Integrated Traffic System) information is performed by an interrupt, the suspended reproduction of the music information or the like is performed by returning to the time point of the interrupt after the reproduction of the ITS information ends. Further, the method is also developed which reproduces music information by changing the tone or the like of the music so that other information also can be received during reproduction of the music information (for example, see Patent Document 2).    Patent Document 1: Japanese Patent Application Laid-Open No. 2003-85689    Patent Document 2: Japanese Patent Application Laid-Open No. 2007-86316